1. Field of the Invention
The present invention relates to the field of integrated circuit design; more specifically, it relates to a method for distributing power in an integrated circuit.
2. Background of the Invention
In an effort to increase performance, lower power consumption and integrate several integrated circuit technologies on the same chip, the concept of voltage islands has been introduced into integrated circuit design.
The voltage island concept allows for one or more portions of an integrated chip (islands) to be powered by both a chip wide power source (VDDg) and one or more additional, voltage island power sources (VDDi through VDDn.) VDDg and VDDi through VDDn can be switched on and off by the user as the operation of the integrated circuit demands. VDDg, VDDi through VDDn and also GND are supplied to the voltage island from separate chip wide power sources.
Efficiently designing power connections to voltage island circuits from VDDg, VDDi through VDDn and GND is a significant concern. Problems to be overcome include how not to require an overabundance of power wires to anticipate the power needs of unplaced voltage islands, how not to restrict placement of power service terminals (PST""s) contained within the voltage island circuits, because of a locally sparse power grid, how to avoid IR and electro-migration viloations and generally how to avoid blocked pins and other wireability issues.
A first aspect of the present invention is a method of routing power from a power network to one or more power service terminals within a voltage island, comprising: dividing the power network into segments; creating power service terminal to segment connections based on a first set of criteria; removing selected power service terminal to segment connections based on a second set of criteria; and selecting one power service terminal to segment connection for each the power service terminal.
A second aspect of the present invention is a computer system comprising a processor, an address/data bus coupled to the processor, and a computer-readable memory unit coupled to communicate with the processor, the memory unit containing instructions that when executed implement a method for routing power from a power network to one or more power service terminals within a voltage island, the method comprising the computer implemented steps of: dividing the power network into segments; creating power service terminal to segment connections based on a first set of criteria; removing selected power service terminal to segment connections based on a second set of criteria; and selecting one power service terminal to segment connection for each the power service terminal.
A third aspect of the present invention is a program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for routing power from a power network to one or more power service terminals within a voltage island the method steps comprising: dividing the power network into segments; creating power service terminal to segment connections based on a first set of criteria; removing selected power service terminal to segment connections based on a second set of criteria; and selecting one power service terminal to segment connection for each the power service terminal.